Light emitting diode

ABSTRACT

The invention provides an LED including a first-type semiconductor layer, an emitting layer, a second-type semiconductor layer, a first electrode, a second electrode, a Bragg reflector structure, a conductive layer and insulation patterns. The first electrode and the second electrode are located on the same side of the Bragg reflector structure. The conductive layer is disposed between the Bragg reflector structure and the second-type semiconductor layer. The insulation patterns are disposed between the conductive layer and the second-type semiconductor layer. Each insulating layer has a first surface facing toward the second-type semiconductor layer, a second surface facing away from the second-type semiconductor layer, and an inclined surface. The inclined surface connects the first surface and the second surface and is inclined with respect to the first surface and the second surface.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part application of and claims thepriority benefit of U.S. application Ser. No. 15/045,279, filed on Feb.17, 2016, now pending. The prior U.S. application Ser. No. 15/045,279claims the priority benefits of U.S. provisional application Ser. No.62/116,923, filed on Feb. 17, 2015, U.S. provisional application Ser.No. 62/151,377, filed on Apr. 22, 2015, and U.S. provisional applicationSer. No. 62/168,921, filed on Jun. 1, 2015. The entirety of each of theabove-mentioned patent applications is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention generally relates to a light emitting diode, and moreparticularly, to a light emitting diode having a Bragg reflectorstructure.

2. Description of Related Art

Recently, the light emission efficiency of the light emitting diode(LED) is sustainably improved. In other aspect, compared with theconventional light bulbs, the LED possesses the following advantages andcharacteristics such as compact volume, long lifetime, lowvoltage/current drive, not easy to be broken, mercury-free (no pollutionproblems), and better light emission efficiency (power saving), etc. Dueto the foregoing advantages, the light emission efficiency of the LEDshave been developed rapidly in recent years such that the conventionallight bulbs are gradually replaced by the LEDs, therefore the LEDsreceive great attention in the lighting and displaying technologies.

Enhancement of the light emission efficiency of the LED is the keyfactor for the LED to be applied in different fields. Generally, oneside of the LED has a distributed Bragg reflector (DBR) structure formedthereon, so as to reflect parts of light emitted from the emitting layerof the LED toward a predetermined emitting direction and enhance thelight extraction efficiency.

SUMMARY OF THE INVENTION

The invention provides a light emitting diode (LED) having preferableproperties.

An embodiment of the invention provides an LED, which includes afirst-type semiconductor layer, an emitting layer, a second-typesemiconductor layer, a first electrode, a second electrode, a Braggreflector structure, a conductive layer and a plurality of insulationpatterns. The emitting layer is located between the first-typesemiconductor layer and the second-type semiconductor layer. The firstelectrode is electrically connected to the first-type semiconductorlayer. The second electrode is electrically connected to the second-typesemiconductor layer. The first electrode and the second electrode arelocated on the same side of the Bragg reflector structure. Theconductive layer is disposed between the Bragg reflector structure andthe second-type semiconductor layer. The insulation patterns aredisposed between the conductive layer and the second-type semiconductorlayer, and an area of the conductive layer outside the insulationpatterns contacts the second-type semiconductor layer. Each insulatinglayer has a first surface facing toward the second-type semiconductorlayer, a second surface facing away from the second-type semiconductorlayer, and an inclined surface. The inclined surface connects the firstsurface and the second surface and is inclined with respect to the firstsurface and the second surface.

In an embodiment of the invention, an acute angle θ1 is formed betweenthe inclined surface and the first surface in a material of each of theinsulation patterns.

In an embodiment of the invention, 10°≦θ1≦80°.

In an embodiment of the invention, 30°≦θ1≦50°.

In an embodiment of the invention, each of the insulation patternsincludes a plurality of first sub-layers and a plurality of secondsub-layers. The first sub-layers and the second sub-layers are stackedalternately.

In an embodiment of the invention, a material of the first sub-layers isdifferent from a material of the second sub-layers.

In an embodiment of the invention, a material of the first sub-layers isthe same as a material of the second sub-layers, and a density of thefirst sub-layers is different from a density of the second sub-layers.

In an embodiment of the invention, the material of each of the firstsub-layers includes tantalum pentoxide (Ta₂O₅), zirconium dioxide(ZrO₂), niobium pentoxide (Nb₂O₅), hafnium oxide (HfO₂), titaniumdioxide (TiO₂), or combinations thereof.

In an embodiment of the invention, a material of each of the secondsub-layers includes silicon dioxide (SiO₂).

In an embodiment of the invention, a material of each of the firstsub-layers is the same as a material of each of the second sub-layers,and a density of each of the first sub-layers is different from adensity of each of the second sub-layers.

In an embodiment of the invention, a reflectance of the Bragg reflectorstructure is greater than or equal to 95% in a reflective wavelengthrange at least covering 0.8X nm to 1.8X nm. The emitting layer isadapted to emit a beam, the beam has a peak wavelength within anemission wavelength range, and X is the peak wavelength of the emissionwavelength range.

In an embodiment of the invention, the first-type semiconductor layerincludes a first portion and a second portion. The emitting layer isstacked on the first portion, and the second portion extends out of anarea of the emitting layer from the first portion, so as to electricallyconnect with the first electrode. The first electrode, the emittinglayer, the second-type semiconductor layer, and the second electrode arelocated on a first side of the first-type semiconductor layer.

In an embodiment of the invention, the Bragg reflector structure islocated on a first side of the first-type semiconductor layer. The Braggreflector structure is at least located between the second electrode andthe second-type semiconductor layer. The Bragg reflector structurecomprises a plurality of through holes. The second electrode is filledinto the through holes to electrically connect with the second-typesemiconductor layer.

In an embodiment of the invention, the insulation patterns correspond tothe through holes.

An embodiment of the invention provides an LED, which includes afirst-type semiconductor layer, an emitting layer, a second-typesemiconductor layer, a first electrode, a second electrode, a Braggreflector structure, a conductive layer and a plurality of insulationpatterns. The emitting layer is located between the first-typesemiconductor layer and the second-type semiconductor layer. The firstelectrode is electrically connected to the first-type semiconductorlayer. The second electrode is electrically connected to the second-typesemiconductor layer. The first electrode and the second electrode arelocated on the same side of the Bragg reflector structure. Theconductive layer is disposed between the Bragg reflector structure andthe second-type semiconductor layer. The insulation patterns aredisposed between the conductive layer and the second-type semiconductorlayer, and an area of the conductive layer outside the insulationpatterns contacts the second-type semiconductor layer. Each of theinsulation patterns includes a plurality of first sub-layers and aplurality of second sub-layers, and the first sub-layers and the secondsub-layers are alternately stacked.

In an embodiment of the invention, the LED further includes a growthsubstrate. The first-type semiconductor layer, the emitting layer, thesecond-type semiconductor layer, and the Bragg reflector structure aresequentially stacked on a first surface of the growth substrate.

In an embodiment of the invention, the LED further includes a firstinsulating layer and a second insulating layer. The Bragg reflectorstructure is disposed between the first insulating layer and the secondinsulating layer. The first insulating layer is located between theBragg reflector structure and the second-type semiconductor layer. Thesecond insulating layer is located between the Bragg reflector structureand the second electrode.

In an embodiment of the invention, a material of the first sub-layers isdifferent from a material of the second sub-layers.

In an embodiment of the invention, a material of the first sub-layers isthe same as a material of the second sub-layers, and a density of thefirst sub-layers is different from a density of the second sub-layers.

In an embodiment of the invention, the material of each of the firstsub-layers includes tantalum pentoxide (Ta₂O₅), zirconium dioxide(ZrO₂), niobium pentoxide (Nb₂O₅), hafnium oxide (HfO₂), titaniumdioxide (TiO₂), or combinations thereof.

In an embodiment of the invention, a material of each of the secondsub-layers includes silicon dioxide (SiO₂).

In an embodiment of the invention, a material of each of the firstsub-layers is the same as a material of each of the second sub-layers,and a density of each of the first sub-layers is different from adensity of each of the second sub-layers.

In an embodiment of the invention, a reflectance of the Bragg reflectorstructure is greater than or equal to 95% in a reflective wavelengthrange at least covering 0.8X nm to 1.8X nm. The emitting layer isadapted to emit a beam, the beam has a peak wavelength within anemission wavelength range, and X is the peak wavelength of the emissionwavelength range.

In an embodiment of the invention, the first-type semiconductor layerincludes a first portion and a second portion. The emitting layer isstacked on the first portion, and the second portion extends out of anarea of the emitting layer from the first portion, so as to electricallyconnect with the first electrode. The first electrode, the emittinglayer, the second-type semiconductor layer, and the second electrode arelocated on a first side of the first-type semiconductor layer.

In an embodiment of the invention, the Bragg reflector structure islocated on a first side of the first-type semiconductor layer. The Braggreflector structure is at least located between the second electrode andthe second-type semiconductor layer. The Bragg reflector structurecomprises a plurality of through holes. The second electrode is filledinto the through holes to electrically connect with the second-typesemiconductor layer.

In an embodiment of the invention, the insulation patterns correspond tothe through holes.

Based on the above, the sidewall of the Bragg reflector structure in thelight emitting diode according to an embodiment of the invention is aninclined surface. Therefore, a layer disposed on the Bragg reflectorstructure may properly cover the Bragg reflector structure, so as tofacilitate the performance of the light emitting diode.

To make the aforesaid features and advantages of the invention morecomprehensible, several embodiments accompanied with drawings aredescribed in details as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1A is a schematic cross-sectional view of an LED according to anembodiment of the invention.

FIG. 1B is a reflection spectrum of a Bragg reflector structureaccording to an embodiment of the invention.

FIG. 1C is a reflection spectrum of a Bragg reflector structureaccording to an embodiment of the invention.

FIG. 2 is a schematic cross-sectional view of an LED according toanother embodiment of the invention.

FIG. 3 is a schematic cross-sectional view of an LED according toanother embodiment of the invention.

FIG. 4 is a schematic cross-sectional view of an LED according to oneother embodiment of the invention.

FIG. 5 is a schematic cross-sectional view of an LED according to yetanother embodiment of the invention.

FIG. 6 is a schematic cross-sectional view of a metal layer according toan embodiment of the invention.

FIG. 7 is a schematic top view of an LED according to an embodiment ofthe invention.

FIG. 8 is a schematic cross-sectional view along a line A-Bcorresponding to FIG. 7.

FIG. 9 is a schematic cross-sectional view along a line B-Ccorresponding to FIG. 7.

FIG. 10 is a schematic cross-sectional view along a line C-Dcorresponding to FIG. 7.

FIG. 11 is a schematic cross-sectional view along a line E-Fcorresponding to FIG. 7.

FIG. 12 is a schematic cross-sectional view along a line G-Hcorresponding to FIG. 7.

FIG. 13 is a schematic cross-sectional view of a Bragg reflectorstructure according to an embodiment of the invention.

FIG. 14 is a schematic cross-sectional view of a Bragg reflectorstructure according to another embodiment of the invention.

FIG. 15 is a schematic cross-sectional view of a Bragg reflectorstructure according to one other embodiment of the invention.

FIG. 16 is a schematic cross-sectional view of a Bragg reflectorstructure according to yet another embodiment of the invention.

FIG. 17 is a schematic cross-sectional view of an LED according to anembodiment of the invention.

FIG. 18A is a schematic enlarged view of an insulation pattern and aconductive layer according to an embodiment of the invention.

FIG. 18B is a schematic enlarged view of an insulation pattern and aconductive layer of a comparative example.

FIG. 19A is a schematic view illustrating an insulation patternaccording to an embodiment of the invention.

FIG. 19B is a schematic view illustrating an insulation patternaccording to another embodiment of the invention.

FIG. 20 is a schematic cross-sectional view of an LED according to anembodiment of the invention.

FIG. 21 is a schematic cross-sectional view of an LED according to anembodiment of the invention.

FIG. 22 is a schematic cross-sectional view of an LED according to anembodiment of the invention.

FIG. 23 is a schematic cross-sectional view of an LED according to anembodiment of the invention.

FIG. 24 is a schematic cross-sectional view of an LED according to anembodiment of the invention.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numbers areused in the drawings and the description to refer to the same or likeparts.

FIG. 1A is a schematic cross-sectional view of an LED according to anembodiment of the invention. Referring to FIG. 1A, specifically, FIG. 1Aillustrates a horizontal type LED, which is an LED applicable to wirebonding. The LED 100 includes a first-type semiconductor layer 110, anemitting layer 120, a second-type semiconductor layer 130, a firstelectrode 140, a second electrode 150, and a Bragg reflector structure160. In the present embodiment, one of the first-type semiconductorlayer 110 and the second-type semiconductor layer 130 is an N-typesemiconductor layer (e.g., n-GaN), and another one is a P-typesemiconductor layer (e.g., p-GaN). The emitting layer 120 is locatedbetween the first-type semiconductor layer 110 and the second-typesemiconductor layer 130, the emitting layer 120 is configured to emit alight beam L, and a light emitting wavelength range of the light beam Lhas a peak wavelength. The first electrode 140 is electrically connectedto the first-type semiconductor layer 110. The second electrode 150 iselectrically connected to the second-type semiconductor layer 130. Thefirst-type semiconductor layer 110, the emitting layer 120, and thesecond-type semiconductor layer 130 are located on the same side of theBragg reflector structure 160. A reflectance of the Bragg reflectorstructure 160 is greater than or equal to 90% in a reflective wavelengthrange at least covering 0.8X nm to 1.8X nm, the reflectance is greaterthan or equal to 95% in a reflective wavelength range at least covering0.9X nm to 1.6X nm, in which X is the peak wavelength of the lightemitting wavelength range.

In an embodiment, the emitting layer 120 may be a quantum well (QW)structure. In other embodiments, the emitting layer 120 may be amultiple quantum well (MQW) structure, in which the MQW structureincludes a plurality of well layer and a plurality of barrier layeralternately disposed in a repeating manner. In addition, a material ofthe emitting layer 120 includes the compositions of compoundsemiconductors capable to emitting the light beam L having the peakwavelength in the range of 320 nm to 430 nm (ultraviolet light), 430 nmto 500 nm (blue light), or 500 nm to 550 nm (green light). The variationin the compositions or structural configurations of the emitting layer120 may alter the light emitting wavelength range of the light beam L,but the invention is not limited thereto.

In detail, in the present embodiment, the first-type semiconductor 110includes a first portion P1 and a second portion P2. The emitting layer120 is stacked on the first portion P1. The second portion P2 extendsout of an area of the emitting layer 120 from the first portion P1, soas to electrically connect with the first electrode 140. The first-typesemiconductor layer 110 includes a first side 111 and a second side 112opposite to the first side 111. The emitting layer 120, the second-typesemiconductor layer 130, the first electrode 140, and the secondelectrode 150 are located on the first side 111 of the first-typesemiconductor layer 110. The Bragg reflector structure 160 is located onthe second side 112 of the first-type semiconductor layer 110.

In particular, the LED 110 of the present embodiment further includes agrowth substrate 170. The growth substrate 170 includes a first surface171 and a second surface 172 opposite to the first surface 171. Amaterial of the substrate 170 is, for example, C-Plane, R-Plane, orA-plane Sapphire substrate or other transparent materials. Additionally,single crystalline compounds having a lattice constant close to thefirst-type semiconductor layer 110 are also suitable to be used as amaterial for the growth substrate 170. The first-type semiconductorlayer 110, the emitting layer 120, and the second-type semiconductorlayer 130 of the present embodiment are sequentially grown and stackedon the first surface 171 of the growth substrate 170. The Braggreflector structure 160 is disposed on the second surface 172 of thegrowth substrate 170. In other embodiments, the LED 110 may not have thegrowth substrate 170, and the Bragg reflector structure 160 is disposedon the second side 112 of the first-type semiconductor layer 110.

Generally, the light beam L emitted from the emitting layer 120 emitstoward all directions, for example, the light beam L1 and the light beamL2 emit toward different directions from the emitting layer 120.However, when the emitting direction of the light beam L1 is configuredas the main emitting direction of the LED 110, the light beam L2 may notbe utilized, causing the limitation to the light emission efficiency.Therefore, in the present embodiment, the Bragg reflector structure 160is used for reflecting the light beam L2 traveling downward and guidingthe light beam L2 toward the upper side of the growth substrate 170,that is the reflecting light beam L2′. In this way, the light beamemitted from the emitting layer 120 can be effectively emitted toward apredetermined emitting direction, with an excellent light emissionefficiency.

In particular, the Bragg reflector structure 160 is mainly formed by acombination of at least one primary stacked layer region, at least onebuffer stacked layer region, and at least one repair stacked layerregion. The primary stacked layer region, the buffer stacked layerregion, and the repair stacked layer region respectively includes aplurality of first refractive layers 162 and a plurality of secondrefractive layers 164, and the first refractive layers 162 and thesecond refractive layers 164 are stacked alternately. A refractive indexof each of the first refractive layers 162 is different from arefractive index of each of the second refractive layers 164. The bufferstacked layer region may be located between two adjacent primary stackedlayer regions, so as to increase the reflectance of the two adjacentprimary stacked layer regions. The repair stacked layer region is atleast located on one side of the primary stacked layer region, so as toincrease the reflectance of the primary stacked layer region. Inaddition, a structure for increasing the reflectance of the Braggreflector structure is added, in which the buffer stacked layer regionmay be located between two adjacent repair stacked layer regions and theprimary stacked layer region may be located between two repair stackedlayer regions, so as to increase the reflectance of the two adjacentprimary stacked layer regions. In other words, the Bragg reflectorstructure 160 is formed by periodic structure, partial periodicstructure, gradually increasing structure, or gradually decreasingstructure of alternately stacked first refractive layers 162 and secondrefractive layers 164. That is, in the Bragg reflector structure 160,one of the at least one pair of the adjacent two layers is the firstrefractive layer 162 and another one is the second refractive layer 164.In an embodiment, materials and thicknesses of the first refractivelayers 162 and the second refractive layers 164 are respectively relatedto the reflective wavelength range of the Bragg reflector structure 160.The structures of the primary stacked layer region, the buffer stackedlayer region, or the repair stacked layer region are formed by arrangingthe first refractive layers 162 and the second refractive layers 164alternately, and may be formed by the same periodic structure, adifferent periodic structure, a gradually increasing structure, or agradually decreasing structure. A number of the layers of the periodicstructure, the partial periodic structure, the gradually increasingstructure, or the gradually decreasing structure of the primary stackedlayer region is larger than the number of the layers of the periodicstructure, the partial periodic structure, the gradually increasingstructure, or the gradually decreasing structure of the buffer stackedlayer region or the repair stacked layer region. The buffer stackedlayer region at least includes a material contained in the two adjacentstacked layer regions, and the material thereof may be the same materialor a material with the same refractive index. Additionally, thicknessesof the first refractive layers 162 and the second refractive layers 164may be the same or different.

A material of the first refractive layers 162 in the present embodimentincludes tantalum pentoxide (Ta₂O₅), zirconium dioxide (ZrO₂), niobiumpentoxide (Nb₂O₅), hafnium oxide (HfO₂), titanium dioxide (TiO₂), orcombinations thereof. On the other hand, a material of the secondrefractive layers 164 includes silicon oxide (SiO₂). By selecting thematerials of the first refractive layer 162 and the second refractivelayer 164, the probability of the light beam L2 being absorbed by thefirst refractive layer 162 and the second refractive layer 164 can bereduced, thereby increasing the possibility of the light beam L2 beingreflected, and thus the light emission efficiency and brightness of theLED 100 can be increased. Especially, in the present embodiment, theBragg reflector structure 160 has excellent reflectance (greater than orequal to 95%) with respect to different reflectance wavelength ranges,thereby allowing the LED 100 to be suitable in applications of lightemitting device which requires to emit different light emittingwavelength ranges. Specifically, if the adjacent first refractive layer162 and second refractive layer 164 are being regarded as a stackedlayer pair, the Bragg reflector structure 160 applied to the LED 100 mayinclude more than or equal to 4 to less than or equal to 100 or evenmore stacked layer pairs. In addition, the number of the stack layerpair can be adjusted according to the desired reflective properties, andit construes no limitation in the invention. For example, 30 to 50stacked layer pairs may be adopted to constitute the Bragg reflectorstructure 160.

If the light beam L provided by the LED 100 is ultraviolet light, thepeak wavelength of the light emitting wavelength range falls in a rangeof 320 nm to 430 nm. Meanwhile, the material of the first refractivelayers 162 in the Bragg reflector structure 160 may be selected frommaterials containing tantalum (Ta) such as tantalum pentoxide (Ta₂O₅),and the material of the second refractive layers 164 may be selectedfrom silicon oxide (SiO₂), but they construe no limitation in theinvention. For example, when the peak wavelength of the light emittingwavelength range is 400 nm, through adjusting the material, thickness,and the number of stacked layer pair in the present embodiment, theBragg reflector structure 160 iscapable to providing a reflectancegreater than or equal to 90% in the reflective wavelength range at leastcovering 320 nm (0.8 times the peak wavelength) to 720 nm (1.8 times thepeak wavelength). Additionally, in other preferable embodiments, whenthe peak wavelength of the light emitting wavelength range is 400 nm,the Bragg reflector structure 160 iscapable to providing a reflectancegreater than or equal to 95% in the reflective wavelength range at leastcovering 360 nm (0.9 times the peak wavelength) to 560 nm (1.4 times thepeak wavelength).

FIG. 1B is a reflection spectrum of a Bragg reflector structureaccording to an embodiment of the invention. In FIG. 1B, the horizontalaxis denotes wavelength and the vertical axis denotes relativereflectance, and the relative reflectance is the reflectance of theBragg reflector structure relative to a reflectance of an aluminiummetal layer. In an embodiment, the Bragg reflector structure having thereflection spectrum illustrated in FIG. 1B utilizes tantalum pentoxide(Ta₂O₅) as the first refractive layers and silicon dioxide (SiO₂) as thesecond refractive layer. Additionally, the first refractive layers andthe second refractive layers in the Bragg reflector structurerespectively includes 30 layers, and the first refractive layers and thesecond refractive layers are stacked alternately in a repeating mannerto form the Bragg reflector structure. As illustrated in FIG. 1B, ascompared with the aluminium metal layer, the Bragg reflector structurehas a relative reflectance higher than 100% in the wavelength range of350 nm to 450 nm. As a result, a light emitting chip having the Braggreflector structure can be used for ultraviolet light emitting device,thereby enhancing the light extraction efficiency of the ultravioletlight emitting device.

Referring to FIG. 1A, if the light beam L provided by the LED 100 isblue light, the peak wavelength of the light emitting wavelength rangefalls in a range of 420 to 500 nm. Meanwhile, the material of the firstrefractive layers 162 in the Bragg reflector structure 160 may beselected from materials containing titanium (Ti) such as titaniumdioxide (TiO₂), and the material of the second refractive layers 164 maybe selected from silicon oxide (SiO₂), but they construe no limitationin the invention. For example, when the peak wavelength of the lightemitting wavelength range is 450 nm, through adjusting the material,thickness, and the number of stacked layer pair in the presentembodiment, the Bragg reflector structure 160 iscapable to providing areflectance greater than or equal to 90% in the reflective wavelengthrange at least covering 360 nm (0.8 times the peak wavelength) to 810 nm(1.8 times the peak wavelength). Additionally, in other embodiments,when the peak wavelength of the light emitting wavelength range is 450nm, the Bragg reflector structure 160 iscapable to providing areflectance greater than or equal to 95% in the reflective wavelengthrange at least covering 405 nm (0.9 times the peak wavelength) to 720 nm(1.6 times the peak wavelength).

If the light beam L provided by the LED 100 is blue light whilecontaining a wavelength conversion structure such as phosphor powderthrough different packing type, the light beam L provided by the LED 100is blue light and can be excited by the wavelength conversion structureto render another peak wavelength of an excitation wavelength. Theanother peak wavelength of the excitation wavelength is greater than thepeak wavelength of the light beam L provided by the LED 100, so as toallow the light beam at least includes more than one peak wavelength,and the peak wavelengths of the light emitting wavelength range and theexcitation wavelength range may fall in a range of 400 nm to 700 nm.Meanwhile, the material of the first refractive layers 162 in the Braggreflector structure 160 may be selected from materials containingtitanium (Ti) such as titanium dioxide (TiO₂), and the material of thesecond refractive layers 164 may be selected from silicon oxide (SiO₂),but they construe no limitation in the invention.

For example, when at least one of the peak wavelength of the lightemitting wavelength range is 445 nm and the peak wavelength of theexcitation wavelength is 580 nm, or in addition, a peak wavelength of anexcitation wavelength of 620 nm may be included, through adjusting thematerial, thickness, and the number of stacked layer pair in the presentembodiment, the Bragg reflector structure 160 iscapable to providing areflectance greater than or equal to 90% in the reflective wavelengthrange at least covering 356 nm (0.8 times the peak wavelength) to 801 nm(1.8 times the peak wavelength). Additionally, in other embodiments,when the peak wavelength of the light emitting wavelength range is 445nm, the Bragg reflector structure 160 iscapable to providing areflectance greater than or equal to 95% in the reflective wavelengthrange at least covering 400.5 nm (0.9 times the peak wavelength) to 712nm (1.6 times the peak wavelength).

If the light beam L provided by the LED 100 is green light, the peakwavelength of the light emitting wavelength range falls in a range of500 nm to 550 nm. Meanwhile, the material of the first refractive layers162 in the Bragg reflector structure 160 may be selected from materialscontaining titanium (Ti) such as titanium dioxide (TiO₂), and thematerial of the second refractive layers 164 may be selected fromsilicon oxide (SiO₂), but they construe no limitation in the invention.For example, when the peak wavelength of the light emitting wavelengthrange is 525 nm, through adjusting the material, thickness, and thenumber of stacked layer pair in the present embodiment, the Braggreflector structure 160 iscapable to providing a reflectance greaterthan or equal to 90% in the reflective wavelength range at leastcovering 420 nm (0.8 times the peak wavelength) to 997.5 nm (1.9 timesthe peak wavelength). Additionally, in other embodiments, when the peakwavelength of the light emitting wavelength range is 525 nm, the Braggreflector structure 160 iscapable to providing a reflectance greaterthan or equal to 95% in the reflective wavelength range at leastcovering 472.5 nm (0.9 times the peak wavelength) to 840 nm (1.6 timesthe peak wavelength).

FIG. 1C is a reflection spectrum of a Bragg reflector structureaccording to another embodiment of the invention. In FIG. 1C, thehorizontal axis denotes wavelength and the vertical axis denotesreflectance. In an embodiment, the Bragg reflector structure having thereflection spectrum illustrated in FIG. 1C utilizes titanium dioxide(TiO₂) as the first reflective layers and silicon dioxide (SiO₂) as thesecond reflective layers. Additionally, the first refractive layers andthe second refractive layers in the Bragg reflector structurerespectively includes 24 layers, and the first refractive layers and thesecond refractive layers are stacked alternately in a repeating mannerto form the Bragg reflector structure. As illustrated in FIG. 1C, in thereflection spectrum of the Bragg reflector structure, the reflectance isapproximately higher than or equal to 90% in the wavelength range of 400nm to 700 nm, and even more, the reflectance is maintained at close to100% in the wavelength range of 400 nm to 600 nm. Since the reflectionspectrum of the Bragg reflector structure has high reflectance in abroader wavelength range, the Bragg reflector structure iscapable toproviding reflection effects in the broader wavelength range for a widerview angle.

The reflection spectrum of the Bragg reflector structure still has ahigh reflectance in a wavelength range slightly lower than 400 nm andcloser to 400 nm, the reflection spectrum of the Bragg reflectorstructure still has a high reflectance in a wavelength range slightlyhigher than 700 nm, and even has a decent reflectance in a wavelengthrange approximately closer to 800 nm. As a result, a light emitting chiphaving the Bragg reflector structure can be used for visible lightemitting device, thereby enhancing the light extraction efficiency ofthe visible light emitting device. Additionally, as illustrated in FIG.1C, the Bragg reflector structure at a longer wavelength range, forexample, 800 nm to 900 nm, or even more than 900 nm, has a reflectancelower than 40%. In this way, the process feasibility of the lightemitting chip having the Bragg reflector structure in laser cutting andbatch sheet can be enhanced.

In the present embodiment, when the light emitting chip having the Braggreflector structure is applied on the light emitting device, theemitting wavelength of the emitting layer of the light emitting chip mayonly cover part of the visible light wavelength range. In addition, thelight emitting device may further include phosphor powder, and theexcitation wavelength of the phosphor powder may cover another part ofthe visible light wavelength range. For example, the emitting wavelengthof the emitting layer may be blue light or green light, and theexcitation wavelength of the phosphor powder may be yellow light, greenlight, or red light, etc. In this way, through the disposition of thelight emitting chip and the phosphor powder, the light emitting devicemay emit white light, and the Bragg reflector structure in the lightemitting chip may efficiently reflect the wavelength range covered bythe white light. In other words, in the light emitting chip, the lightemitting wavelength of the emitting layer and the reflective wavelengthof the Bragg reflector structure can be only partially overlapped, andare not required to be consistent with each other. Certainly, in thelight emitting chip, the light emitting wavelength of the emitting layerand the reflective wavelength of the Bragg reflector structure may alsobe configured corresponding to each other, for example, both fall in thewavelength range of the blue light, both fall in the wavelength range ofthe green light, or both fall in the wavelength range of the red light.

It should be mentioned that reference numerals and some descriptionsprovided in the previous exemplary embodiment are also applied in thefollowing exemplary embodiment. The same reference numerals arepresented to denote identical or similar components in these exemplaryembodiments, and repetitive descriptions are omitted. The omitteddescriptions may be found in the previous exemplary embodiments, andwill not be repeated hereinafter.

FIG. 2 is a schematic cross-sectional view of an LED according toanother embodiment of the invention. FIG. 2 is a schematiccross-sectional view of an LED according to another embodiment of theinvention. Referring to FIG. 2, the LED 100′ illustrated in FIG. 2 is anLED applicable to flip chip packaging. The LED 100′ in the presentembodiment is similar to the LED 100 in FIG. 1A, and the majordifference lies in that: the Bragg reflector structure 160′ is locatedbetween the second electrode 150 and the second-type semiconductor layer130, and the Bragg reflector structure 160′ has a plurality of throughholes 166. In other words, the first-type semiconductor layer 110, theemitting layer 120, the second-type semiconductor layer 130, and theBragg reflector structure 160′ in the present embodiment aresequentially stacked on the first surface 171 of the growth substrate170. In addition, the second electrode 150 is filled into the throughholes 166 to electrically connect with the second-type semiconductorlayer 130.

In particular, in the present embodiment, the LED 100′ further includesa conductive layer 101 and a plurality of insulation patterns 103, andthe insulation patterns 103 may not connect to each other. Theconductive layer 101 is disposed between the Bragg reflector structure160′ and the second-type semiconductor layer 130, and the secondelectrode 150 filled into the through holes 166 may contact theconductive layer 101 to be electrically connected to the second-typesemiconductor 130 via the conductive layer 101. A material of theconductive layer 101 is, for example, indium tin oxide (ITO) or othermaterials having characteristics of current dispersion and allowinglight to pass through.

On the other hand, the insulation patterns 103 are disposed between theconductive layer 101 and the second-type semiconductor layer 130, andpart of the insulation patterns 103 are disposed corresponding to thethrough holes 166 such that an area of the conductive layer 101 outsideof the insulation patterns 103 contacts the second-type semiconductorlayer 130. To take a step further, a material of the insulation patterns103 includes, for example, silicon dioxide (SiO₂) or other materialshaving characteristic of current blocking. The conductive layer 101 andthe insulation patterns 103 are disposed to uniformly disperse thecurrent transferred in the emitting layer 130 to avoid the current fromconcentrating at certain part of the emitting layer 120, therebyallowing uniform distribution of the light emitting region of theemitting layer 120. Therefore, the above configuration enables betterlight emitting uniformity of the LED 100′.

In the present embodiment, since the LED 100′ is a flip chip packagingtype LED, an insulating layer 105 and an electrode pad 107 may furtherbe disposed on the second electrode 150. The insulating layer 105 has athrough hole O1, and the electrode pad 107 is filled into the throughholes O1, so that the electrode pad 107 is electrically connected to thesecond electrode 150. In order to electrically connect or physicallyconnect with an external substrate during the bonding process of theflip chip, a material of the electrode pad 107 and the first electrode140 is, for example, gold (Au), gold/tin (Au/Sn) alloy, or otherconductive materials applicable in eutectic bonding. Herein, the firstelectrode 140 can be used for eutectic bonding directly, but itconstrues no limitation in the invention. In other embodiments, thefirst electrode 140 and the second electrode 150 may be formed by thesame material, and an additional electrode pad used for eutectic bondingcan be disposed above the first electrode 140.

In the present embodiment, the specific configuration and the materialof the Bragg reflector structure 160′ can be the same as the Braggreflector structure 160 in the previous embodiment. Therefore, thereflectance of the Bragg reflector structure 160′ has an excellentperformance in the short wavelength range, thereby allowing the LED 100′also to be suitable in applications of light emitting device whichrequires to emit at the short wavelength range.

FIG. 3 is a schematic cross-sectional view of an LED according toanother embodiment of the invention. Referring to FIG. 3, the LEDillustrated in FIG. 3 is another LED applicable to flip chip packaging.The LED 200′ in the present embodiment is similar to the LED 100′ inFIG. 2, and the major difference lies in that: the Bragg reflectorstructure 260′ is located between the second electrode 150 and thesecond-type semiconductor 130, and the Bragg reflector structure 160′has a plurality of through holes 166 located between the secondelectrode 150 and the second-type semiconductor 130 and a plurality ofthrough holes 167 located between the first electrode 140 and thefirst-type semiconductor 110. In other words, the first-typesemiconductor layer 110, the emitting layer 120, the second-typesemiconductor layer 130, and the Bragg reflector structure 260′ in thepresent embodiment are sequentially stacked on the first surface 171 ofthe growth substrate 170. In addition, the second electrode 150 isfilled into the through holes 166 to electrically connect with thesecond-type semiconductor layer 130 and the first electrode 140 isfilled into the through holes 166 to electrically connect with thefirst-type semiconductor layer 110. Although only one through hole 167is illustrated in FIG. 3, in the specific implementation, number of thethrough hole 167 may be adjusted based on the actual configuration.

In particular, in the present embodiment, the LED 200′ further includesa conductive layer 101 and a plurality of insulation patterns 103, andthe insulation patterns 103 may not connect to each other. Theconductive layer 101 is disposed between the Bragg reflector structure260′ and the second-type semiconductor layer 130, and the secondelectrode 150 filled into the through holes 166 may contact theconductive layer 101 to be electrically connected to the second-typesemiconductor 130 via the conductive layer 101. A material of theconductive layer 101 is, for example, indium tin oxide (ITO) or othermaterials having characteristics of current dispersion and allowinglight to pass through.

On the other hand, the insulation patterns 103 are disposed between theconductive layer 101 and the second-type semiconductor layer 130, andpart of the insulation patterns 103 are disposed corresponding topositions of the through holes 166 such that an area of the conductivelayer 101 outside of the insulation patterns 103 contacts thesecond-type semiconductor layer 130. To take a step further, a materialof the insulation patterns 103 includes, for example, silicon dioxide(SiO₂) or other materials having characteristic of current blocking. Theconductive layer 101 and the insulation patterns 103 are disposed touniformly disperse the current transferred in the emitting layer 130 toavoid the current from concentrating at certain part of the emittinglayer 120, thereby allowing uniform distribution of the light emittingregion of the emitting layer 120. Therefore, the above configurationenables better light emitting uniformity of the LED 200′.

Additionally, in the present embodiment, the LED 200′ further includesat least one first metal layer 180 located between the first electrode140 and the first-type semiconductor layer 110 and at least one secondmetal layer 190 located between the second electrode 150 and thesecond-type semiconductor layer 130. Part of the Bragg reflectorstructure 260′ is located on the first metal layer 180 or the secondmetal layer 190. In other words, the first-type semiconductor layer 110,the emitting layer 120, the second-type semiconductor layer 130, and theBragg reflector structure 260′ in the present embodiment aresequentially stacked on the first surface 171 of the growth substrate170. In addition, the first electrode 140 is filled into the throughholes 167 to electrically connect with the first type semiconductorlayer 110 through the first metal layer 180, and the second electrode150 is filled into the through holes 166 to electrically connect withthe second-type semiconductor layer 130 through the second metal layer190.

In the present embodiment, on the other hand, the LED 200′ furtherincludes a first insulating layer 105 a and a second insulating layer105 b. The first insulating layer 105 a is disposed on the first-typesemiconductor layer 110, the second-type semiconductor layer 130, andsidewalls of the first-type semiconductor layer 110, the emitting layer120, and the second-type semiconductor layer 130. The first insulatinglayer 105 a may further dispose on part of the first metal layer 180,part of the second metal layer 190, and the conductive layer 101, and atleast part of the Bragg reflector structure 260′ is located between thefirst insulating layer 105 a and the second insulating layer 105 b.Furthermore, the second insulating layer 105 b may be disposed on theBragg reflector structure 260′. In other words, the first-typesemiconductor layer 110, the emitting layer 120, the second-typesemiconductor layer 130, and the Bragg reflector structure 260′ in thepresent embodiment are sequentially stacked on the first surface 171 ofthe growth substrate 170. In addition, the through holes 166 penetratethrough the second insulating layer 105 b, the Bragg reflector structure260′, and the first insulating layer 105 a, so as to allow the secondelectrode 150 to fill into the through holes 166 and to electricallyconnect with the second metal layer 190 and the second-typesemiconductor layer 130. Similarly, the through holes 167 penetratethrough the second insulating layer 105 b, the Bragg reflector structure260′, and the first insulating layer 105 a, so as to allow the firstelectrode 140 to fill into the through holes 167 and to electricallyconnect with the first metal layer 180 and the first-type semiconductorlayer 110. A material of the first insulating layer 105 a and the secondinsulating layer 105 b includes, for example, silicon dioxide (SiO₂), orthe material thereof may be the same material or a material with thesame refractive index. Moreover, the material of the first insulatinglayer 105 a and the second insulating layer 105 b may further include amaterial contained in the Bragg reflector structure 260′.

In the present embodiment, in order to electrically connect orphysically connect with an external substrate during the bonding processof the flip chip, a material of the first electrode 140 and the secondelectrode 150 is, for example, gold/tin (Au/Sn) alloy or otherconductive materials applicable in eutectic bonding. Herein, the firstelectrode 140 and the second electrode 150 can be used for eutecticbonding directly, but they construe no limitation in the invention. Inother embodiments, the first electrode 140 and the second electrode 150may be formed by the same material.

FIG. 4 is a schematic cross-sectional view of an LED according to oneother embodiment of the invention. Referring to FIG. 4, the LEDillustrated in FIG. 4 is an LED applicable to flip chip packaging. TheLED 300′ in the present embodiment is similar to the LED chip 200′ inFIG. 3, and the major difference lies in that: the LED 300′ furtherincludes a first insulating layer 105 a and a second insulating layer105 b, the Bragg reflector structure 360′ is disposed between the firstinsulating layer 105 a and the second insulating layer 105 b, and thefirst insulating layer 105 a and the second insulating layer 105 b maybe partially overlapped and in contact with each other. The firstinsulating layer 105 a is disposed on the first-type semiconductor layer110, the second-type semiconductor layer 130, and sidewalls of thefirst-type semiconductor layer 110, the emitting layer 120, and thesecond-type semiconductor layer 130. The first insulating layer 105 amay further dispose on part of the first metal layer 180, part of thesecond metal layer 190, and the conductive layer 101, and the Braggreflector structure 360′ is located between the first insulating layer105 a and the second insulating layer 105 b. Furthermore, the secondinsulating layer 105 b may be disposed on the Bragg reflector structure360′, the first insulating layer 105 a, part of the first metal layer180, and part of the second metal layer 190, and the second insulatinglayer 105 b may clad the Bragg reflector structure 360′. In other words,the first-type semiconductor layer 110, the emitting layer 120, thesecond-type semiconductor layer 130, and the Bragg reflector structure360′ in the present embodiment are sequentially stacked on the firstsurface 171 of the growth substrate 170. In addition, the through holes166 penetrate through the second insulating layer 105 b and the firstinsulating layer 105 a, so as to allow the second electrode 150 to fillinto the through holes 166 and to electrically connect with the secondmetal layer 190 and the second-type semiconductor layer 130. Similarly,the through holes 167 penetrate through the second insulating layer 105b and the first insulating layer 105 a, so as to allow the firstelectrode 140 to fill into the through holes 167 and to electricallyconnect with the first metal layer 180 and the first-type semiconductorlayer 110. A material of the first insulating layer 105 a and the secondinsulating layer 105 b includes, for example, silicon dioxide (SiO₂), orthe material thereof may be the same material or a material with thesame refractive index. Moreover, the material of the first insulatinglayer 105 a and the second insulating layer 105 b may further include amaterial contained in the Bragg reflector structure 360′.

FIG. 5 is a schematic cross-sectional view of an LED according to yetanother embodiment of the invention. FIG. 5 is a schematiccross-sectional view of an LED according to yet another embodiment ofthe invention. Referring to FIG. 5, the LED illustrated in FIG. 5 isanother LED applicable to flip chip packaging. The LED 400′ in thepresent embodiment is similar to the LED 300′ in FIG. 4, and the majordifference lies in that: the first metal layer 180 includes a weldingportion 180 a and a finger portion 180 b, the second metal layer 190includes a welding portion 190 a and a finger portion 190 b, and thefirst insulating layer 105 a and the second insulating layer 105 b maybe partially overlapped and in contact with each other. The firstinsulating layer 105 a is disposed on the first-type semiconductor layer110, the second-type semiconductor layer 130, and sidewalls of thefirst-type semiconductor layer 110, the emitting layer 120, and thesecond-type semiconductor layer 130. In addition, the first insulatinglayer 105 a is disposed on part of the first metal layer 180, part ofthe second metal layer 190, and the conductive layer 101, and the firstinsulating layer 105 is disposed on part of the welding portion 180 a ofthe first metal layer 180 and the finger portion 180 b of first metallayer 180. Part of the Bragg reflector structure 360′ is located betweenthe first insulating layer 105 a and the second insulating layer 105 b.Furthermore, the second insulating layer 105 b may be disposed on theBragg reflector structure 360′, the first insulating layer 105 a, partof the first metal layer 180, and part of the second metal layer 190,the second insulating layer 105 b may further clad the Bragg reflectorstructure 360′, and the second insulating layer 105 b is disposed onpart of the welding portion 180 a of the first metal layer 180 and thefinger portion 180 b of the first metal layer 180. In other words, thefirst-type semiconductor layer 110, the emitting layer 120, thesecond-type semiconductor layer 130, and the Bragg reflector structure360′ in the present embodiment are sequentially stacked on the firstsurface 171 of the growth substrate 170. The through holes 166 penetratethrough the second insulating layer 105 b and the first insulating layer105 a, so as to allow the second electrode 150 to fill into the throughholes 166 and to electrically connect with the welding portion 190 a ofthe second metal layer 190 and the second-type semiconductor layer 130.The through holes 167 penetrate through the second insulating layer 105b and the first insulating layer 105 a, so as to allow the firstelectrode 140 to fill into the through holes 167 and to electricallyconnect with the welding portion 180 a of the first metal layer 180 andthe first-type semiconductor layer 110. A material of the firstinsulating layer 105 a and the second insulating layer 105 b includes,for example, silicon dioxide (SiO₂), or the material thereof may be thesame material or a material with the same refractive index. Moreover,the material of the first insulating layer 105 a and the secondinsulating layer 105 b may further include a material contained in theBragg reflector structure 360′.

FIG. 6 is a schematic cross-sectional view of a metal layer according toan embodiment of the invention. FIG. 6 is a schematic cross-sectionalview of a metal layer according to an embodiment of the invention.Referring to FIG. 6, the metal layer M includes a top surface MT, abottom surface MB, and side surfaces MS. The side surfaces MS and thebottom surface MB form an included angle Θ, and the included angle Θ maybe less than or equal to 60 degree, or less than or equal to 45 degree.For example, the included angle Θ can may be 30 degree to 45 degree. Themetal layer M can be used in at least one of the first metal layer 180and the second metal layer 190 in the previous embodiments.

Specifically, when the metal layer M is applied to the first metal layer180 in FIG. 3, an area of the holes 167 can be set to fall on an area ofthe top surface MT, and the side surfaces MS may be at least partiallycovered by the first insulating layer 105 a. Meanwhile, since theincluded angle Θ formed by the side surfaces MS and the bottom surfaceMB may be less than or equal to 60 degree, the first insulating layer105 a can reliably cover on the side surfaces MS. In other words, thefirst insulating layer 105 a has an excellent coverage effect forcovering part of the metal layer M. Similarly, when the metal layer M isapplied to the second metal layer 190 in FIG. 3 or at least one of thefirst metal layer 180 and the second metal layer 190 in FIG. 4 and FIG.5, the similar effects may be provided.

FIG. 7 is a schematic top view of an LED according to an embodiment ofthe invention. FIG. 8 is a schematic cross-sectional view along a lineA-B corresponding to FIG. 7. FIG. 9 is a schematic cross-sectional viewalong a line B-C corresponding to FIG. 7. FIG. 10 is a schematiccross-sectional view along a line C-D corresponding to FIG. 7. FIG. 11is a schematic cross-sectional view along a line E-F corresponding toFIG. 7. FIG. 12 is a schematic cross-sectional view along a line G-Hcorresponding to FIG. 7. In the present embodiment, the LED 500generally includes a conductive layer 110, insulation patterns 103, afirst-type semiconductor layer 110, an emitting layer 120, a second-typesemiconductor layer 130, a first electrode 140, a second electrode 150,a Bragg reflector structure 560′, a growth substrate 170, a first metallayer 180, and a second metal layer 190. Some of the elements are notillustrated in FIG. 7 and are presented in the cross-sectional viewscorresponding to lines A-B, B-C, C-D, E-F, and G-H.

As illustrated in FIG. 7, the first electrode 140 and the secondelectrode 150 of the LED 500 are disposed opposite to each other and areseparated from each other. The first electrode 140 is substantiallyrectangular and sidewall S140 of the first electrode 140 facing thesecond electrode 150 has a plurality of recesses N140. The recesses N140extend from the sidewall S140 toward an interior of the first electrode140 but does not penetrate through the first electrode 140. The secondelectrode 150 is also substantially rectangular and sidewall S150 of thesecond electrode 150 facing the first electrode 140 has a plurality ofrecesses N150. The recesses N150 extend from the sidewall S150 toward aninterior of the second electrode 150 but does not penetrate through thesecond electrode 150. A material of the first electrode 140 and thesecond electrode 150 is, for example, gold (Au), gold/tin (Au/Sn) alloy,or other conductive materials applicable in eutectic bonding. In otherembodiments, the first electrode 140 and the second electrode 150 may beformed by the same material, and an additional electrode pad which isused for eutectic bonding can be disposed above the first electrode 140and the second electrode 150.

In the present embodiment, the welding portion 180 a of the first metallayer 180 overlaps the first electrode 140. The finger portion 180 b ofthe first metal layer 180 extends from the welding portion 180 a towardthe second electrode 190, and in particular, extends into the recessesN150 of the second electrode 150. As illustrated in FIG. 7, the fingerportion 180 b and the second electrode 150 are not overlapped with eachother on the layout area. The welding portion 190 a of the second metallayer 190 overlaps the second electrode 150. The finger portion 190 b ofthe second metal layer 190 extends from the welding portion 190 a towardthe first electrode 180, and in particular, extends into the recessesN140 of the first electrode 140.

As illustrated in FIG. 7, the finger portion 190 b and the firstelectrode 140 are not overlapped with each other on the layout area. Aprofile of the conductive layer 101 surrounds the first metal layer 180and does not overlap with the first metal layer 180. The insulationpatterns 103 are disposed corresponding to the second metal layer 190,and profiles of the insulation patterns 103 are substantially similar tothe profile of the second metal layer 190. Moreover, a profile of theBragg reflector structure 560′ correspondingly exposes the weldingportion 180 a of the first metal layer 180 and the welding portion 190 aof the second metal layer 190. That is, the welding portion 180 a of thefirst metal layer 180 and the welding portion 190 a of the second metallayer 190 do not overlap the Bragg reflector structure 560′, so as toprovide the welding portion 180 a of the first metal layer 180 tophysically and electrically connect with the first electrode 140 and toprovide the welding portion 190 a of the second metal layer 190 tophysically and electrically connected with the second electrode 150.However, the finger portion 180 b of the first metal layer 180 and thefinger portion 190 b of the second metal layer 190 may overlap the Braggreflector structure 560′.

As illustrated in FIG. 7 and FIG. 8, in the LED 500, the first-typesemiconductor layer 110, the emitting layer 120, the second-typesemiconductor layer 130, the conductive layer 101, the Bragg reflectorstructure 560′, and the second electrode 150 are sequentially stacked onthe growth substrate 170. In the stacked structure of the first-typesemiconductor layer 110, the emitting layer 120, and the second-typesemiconductor layer 130, the emitting layer 120 and the second-typesemiconductor layer 130 are partially removed and the conductive layer110 is correspondingly disconnected in this region to expose thefirst-type semiconductor layer 110. The first metal layer 180 isdisposed on the exposed first-type semiconductor layer 110. The firstmetal layer 180 illustrated in FIG. 8 is the finger portion 180 b, thefinger portion 180 b is correspondingly located within the recesses N150of the second electrode 150 and thus is not overlapped with the secondelectrode 150. Moreover, the Bragg reflector structure 560′ overlaps thefinger portion 180 b.

As illustrated in FIG. 7 and FIG. 9, between the sidewall S140 of thefirst electrode 140 and the sidewall S150 of the second electrode 150,the first-type semiconductor layer 110, the emitting layer 120, thesecond-type semiconductor layer 130, the conductive layer 101, and theBragg reflector structure 560′ are distributed continuously, and theseelements are sequentially stacked on the growth substrate 170.

As illustrated in FIG. 7 and FIG. 10, at the recesses N140 of the firstelectrode 140, the first-type semiconductor layer 110, the emittinglayer 120, the second-type semiconductor layer 130, the insulationpatterns 103, the conductive layer 101, the second metal layer 190, andthe Bragg reflector structure 560′ are sequentially stacked on thegrowth substrate 170. The profiles of the insulation patterns 103correspond to the profile of the second metal layer 190 and the two areoverlapped with each other. Specifically, the second metal layer 190illustrated in FIG. 10 is the finger portion 190 b of the second metallayer 190, the finger portion 190 b is correspondingly located withinthe recesses N140 of the first electrode 140 and thus is not overlappedwith the first electrode 140. Moreover, the Bragg reflector structure560′ overlaps the finger portion 190 b.

As illustrated in FIG. 7 and FIG. 11, in the LED 500, the first-typesemiconductor layer 110, the emitting layer 120, the second-typesemiconductor layer 130, the conductive layer 101, the Bragg reflectorstructure 560′, and the second electrode 150 are sequentially stacked onthe growth substrate 170. In the stacked structure of the first-typesemiconductor layer 110, the emitting layer 120, and the second-typesemiconductor layer 130, the emitting layer 120 and the second-typesemiconductor layer 130 are partially removed and the conductive layer101 and the Bragg reflector structure 560′ are correspondinglydisconnected in this region to expose the first-type semiconductor layer110. The first metal layer 180 is disposed on the exposed first-typesemiconductor layer 110, and the first electrode 140 is filled into thedisconnected location of the conductive layer 101 and the Braggreflector structure 560′ to physically and electrically connect with thefirst metal layer 180. In FIG. 11, the welding portion 180 a of thefirst metal layer 180 is illustrated. Therefore, as illustrated in FIG.8 and FIG. 11, the welding portion 180 a of the first metal layer 180 isdirectly in contact and is electrically connected to the firstelectrode, and the finger portion 180 b of the first metal layer 180 isoverlapped with the Bragg reflector structure 560′ and is not overlappedwith any electrode.

As illustrated in FIG. 7 and FIG. 12, in an area occupied by the secondelectrode 150, the first-type semiconductor layer 110, the emittinglayer 120, the second-type semiconductor layer 130, the insulationpatterns 103, the conductive layer 101, the second metal layer 190, andthe Bragg reflector structure 560′ are sequentially stacked on thegrowth substrate 170. The profiles of the insulation patterns 103correspond to the profile of the second metal layer 190 and the two areoverlapped with each other. Specifically, in FIG. 12, the weldingportion 190 a of the second metal layer 190 is overlapped with thesecond electrode 150 and the Bragg reflector structure 560′ isdisconnected in a region corresponding to the welding portion 190 a, soas to allow the welding portion 190 a of the second metal layer 190 tophysically and electrically connect with the second electrode 150. Inother words, the welding portion 190 a of the second metal layer 190 isnot overlapped with the Bragg reflector structure 560′. Comparatively,in FIG. 10, the welding portion 190 b of the second metal layer 190 isoverlapped with the Bragg reflector structure 560′, but is notoverlapped with any electrode.

As illustrated in FIG. 7 to FIG. 12, both the first metal layer 180 andthe second metal layer 190 include a part overlapped with the Braggreflector structure 560′ and another part not overlapped with the Braggreflector structure 560′. The part of the metal layer (180 or 190)overlapped with the Bragg reflector structure 560′ does not overlap withthe electrode. In this way, the thickness of the LED 500 may be moreuniform, which helps to improve the yield when bonding the LED 500 toother components. In addition, in FIG. 7 to FIG. 12, the firstinsulating layer 105 a and the second insulating layer 105 b illustratedin FIG. 4 or FIG. 5 may be disposed on top and bottom sides of the Braggreflector structure 560′ additionally, and the limitation where theBragg reflector structure 560′ directly contacts the conductive layer101, the first electrode 140, the second electrode 150, the first metallayer 180 (finger portion 180 b) and the second metal layer 190 (fingerportion 190 b) is not required. Additionally, the cross-sectionalstructure of the first metal layer 180 and the second metal layer 190may include inclined sidewalls MS as illustrated in FIG. 6.

FIG. 13 is a schematic cross-sectional view of a Bragg reflectorstructure according to an embodiment of the invention. Referring to FIG.13, a Bragg reflector structure DBR1 is disposed between a firstinsulating layer I1 and a second insulating layer I2. The Braggreflector structure DBR1 includes a plurality of first refractive layers12 and a plurality of second refractive layers 14, and the firstrefractive layers 12 and the second refractive layers 14 are stackedalternately. A refractive index of each of the first refractive layers12 is different from a refractive index of each of the second refractivelayers 14. In the present embodiment, thicknesses of the firstrefractive layers 12 and the second refractive layers 14 decrease asthey come closer to the second insulating layer I2. That is, thestacking density of the first refractive layers 12 and the secondrefractive layers 14 increases as they come closer to the secondinsulating layer 12 while decreases as they come closer to the firstinsulating layer I1. As a result, the Bragg reflector structure DBR1 isa structure having a reflective layer density gradually increases formthe first insulating layer I1 to the second insulating layer I2.

A material of the first refractive layers 12 in the present embodimentincludes tantalum pentoxide (Ta₂O₅), zirconium dioxide (ZrO₂), niobiumpentoxide (Nb₂O₅), hafnium oxide (HfO₂), titanium dioxide (TiO₂), orcombinations thereof. On the other hand, a material of the secondrefractive layers 14 includes silicon oxide (SiO₂). In the presentembodiment, the material of the first insulating layer I1 and the secondinsulating layer I2 may also be silicon dioxide (SiO₂). However, whenthe material of the second refractive layers 14, the first insulatinglayer I1, and the second insulating layer I2 are all silicon dioxide(SiO₂), a crystallinity and a compactness of the second refractivelayers 14 are relatively smaller than the first insulating layer I1 andthe second insulating layer I2. The materials and thicknesses of thefirst refractive layers 12 and the second refractive layers 14 mayadjust the reflective wavelength range of the Bragg reflector structureDBR1. Therefore, by adapting the first refractive layers 12 and thesecond refractive layers 14 having thicknesses gradient in the Braggreflector structure DBR1 of the present embodiment, the Bragg reflectorstructure DBR1 may have a broader reflective wavelength range to besuitable in end products requiring light emitting effect in broadwavelength range.

For example, when titanium dioxide (TiO₂) is used to fabricate the firstreflective layers 12 and silicon dioxide (SiO₂) is used to fabricate thesecond reflective layers 14, the Bragg reflector structure DBR1 with thethickness gradient exhibited in the reflective layers may be applicableto visible light emitting devices. When tantalum pentoxide (Ta₂O₅) isused to fabricate the first reflective layers 12 and silicon dioxide(SiO₂) is used to fabricate the second reflective layers 14, the Braggreflector structure DBR1 with the thickness gradient exhibited in thereflective layers may be applicable to ultraviolet light emittingdevices. However, the material and the applications on the lightemitting devices described above are merely used as examples, and inactuality, when the Bragg reflective DBR1 is fabricated by othermaterials, the application thereof may be adjusted based on thereflective wavelength range exhibited.

FIG. 14 is a schematic cross-sectional view of a Bragg reflectorstructure according to another embodiment of the invention. Referring toFIG. 14, a Bragg reflector structure DBR2 is disposed between a firstinsulating layer I1 and a second insulating layer I2. The Braggreflector structure DBR1 includes a plurality of first refractive layers22 and a plurality of second refractive layers 24, and the firstrefractive layers 22 and the second refractive layers 24 are stackedalternately. A refractive index of each of the first refractive layers22 is different from a refractive index of each of the second refractivelayers 24. In the present embodiment, the thicknesses of the firstrefractive layers 22 and the second refractive layers 24 increases asthey come closer to the second insulating layer I2. That is, thestacking density of the first refractive layers 22 and the secondrefractive layers 24 decreases as they come closer to the secondinsulating layer I2 while increases as they come closer to the firstinsulating layer I1. As a result, the Bragg reflector structure DBR2 isa structure having a reflective layer density gradually decreases formthe first insulating layer I1 to the second insulating layer I2.

The materials and thicknesses of the first refractive layers 22 and thesecond refractive layers 24 may adjust the reflective wavelength rangeof the Bragg reflector structure DBR2. A material of the firstrefractive layers 12 includes tantalum pentoxide (Ta₂O₅), zirconiumdioxide (ZrO₂), niobium pentoxide (Nb₂O₅), hafnium oxide (HfO₂),titanium dioxide (TiO₂), or combinations thereof. On the other hand, amaterial of the second refractive layers 24 includes silicon oxide(SiO₂).

FIG. 15 is a schematic cross-sectional view of a Bragg reflectorstructure according to one other embodiment of the invention. Referringto FIG. 15, a Bragg reflector structure DBR3 includes primary stackedlayers B1, B2, a buffer stacked layer C1, and repair stacked layers D1,D2. The primary stacked layer B1 is formed by alternately stacking firstrefractive layers B12 and second refractive layers B14 having arefractive index different from the first refractive layers B12 in arepeating manner. The primary stacked layer B2 is formed by alternatelystacking first refractive layers B22 and second refractive layers B24having a refractive index different from the first refractive layers B22in a repeating manner. The buffer stacked layer C1 is formed byalternately stacking third refractive layers C12 and fourth refractivelayers C14 having a refractive index different from the third refractivelayers C12 in a repeating manner. The repair stacked layer D1 is formedby alternately stacking fifth refractive layers D12 and sixth refractivelayers D14 having a refractive index different from the fifth refractivelayers D12 in a repeating manner. The repair stacked layer D2 is formedby alternately stacking fifth refractive layers D22 and sixth refractivelayers D24 having a refractive index different from the fifth refractivelayers D22 in a repeating manner.

In the present embodiment, the first refractive layers B12 and B22, thethird refractive layers C12, and the fifth refractive layers D11 and D12in the same Bragg reflector structure DBR3 may have the same material ordifferent materials. The material thereof includes tantalum pentoxide(Ta₂O₅), zirconium dioxide (ZrO₂), niobium pentoxide (Nb₂O₅), hafniumoxide (HfO₂), titanium dioxide (TiO₂), or combinations thereof. Thesecond refractive layers B14 and B24, the fourth refractive layers C14,and the sixth refractive layers D14 and D24 in the same Bragg reflectorstructure DBR3 may have the same material or different materials, andthe material thereof includes silicon dioxide (SiO₂).

In addition, in the primary stacked layer B1, each of the firstreflective layers B12 has an equal first thickness Ti and the secondreflective layer B14 has the equal first thickness T1. In the primarystacked layer B2, each of the first reflective layers B22 has an equalsecond thickness T2 and the second reflective layer B24 has the equalsecond thickness T2. Moreover, the first thickness Ti is different fromthe second thickness T2. In other words, a single primary stacked layerB1 or B2 has periodically stacked reflective layers, but the stackedperiod of the reflective layers in different primary stacked layers aredifferent. As a result, by stacking multiple primary stacked layer B1,B2, the Bragg reflector structure DBR3 iscapable to providing a broadreflective wavelength range.

In the buffer stacked layer C1 between the primary stacked layer B1 andthe primary stacked layer B2, the third reflective layers C12 and thefourth reflective layers C14 have a third thickness T3. The thirdthickness T3 may be an average value of the first thickness T1 and thesecond thickness T2. In other words, T3=½(T1+T2). However, thethicknesses of the third reflective layers C12 and the fourth reflectivelayers C14 may be respectively between the first thickness T1 and thesecond thickness T2.

Moreover, the thicknesses of the fifth reflective layers D12 and thesixth reflective layers D14 in the repair stacked layer D1 may approachthe first thickness T1 as they come closer to the primary stacked layerB1. The thicknesses of the fifth reflective layers D22 and the sixthreflective layers D24 in the repair stacked layer D2 may approach thesecond thickness T2 as they come closer to the primary stacked layer B2.That is, the repair stacked layer D1 and the repair stacked layer D2 arestacked structures having thickness gradient in the reflective layers.Moreover, the material composition of the repair stacked layer D1 can berelated to the primary stacked layer B1, and the material composition ofthe repair stacked layer D2 can be related to the primary stacked layerB2.

FIG. 16 is a schematic cross-sectional view of a Bragg reflectorstructure according to yet another embodiment of the invention.Referring to FIG. 16, a Bragg reflector structure DBR4 is similar to theforegoing Bragg reflector structure DBR3, but the Bragg reflectorstructure DBR4 further includes a repair stacked layer D3 and a repairstacked layer D4. The repair stacked layer D3 is located between thebuffer stacked layer C1 and the primary stacked layer B1, and the repairstacked layer D4 is located between the buffer stacked layer C1 and theprimary stacked layer B2. The thicknesses of the reflective layers ofthe repair stacked layer D3 may approach the first thickness T1 as theycome closer to the primary stacked layer B1. The thicknesses of thereflective layers of the repair stacked layer D4 may approach the secondthickness T2 as they come closer to the primary stacked layer B2.Moreover, the material composition of the repair stacked layer D3 can berelated to the primary stacked layer B1, and the material composition ofthe repair stacked layer D4 can be related to the primary stacked layerB2.

The Bragg reflector structures DBR1˜DBR4 in FIG. 13 to FIG. 16 may beapplicable to any one of the LEDs in FIGS. 1, 2, 3, 4, 5, and 7. Thatis, any one of the Bragg reflector structures presented in the foregoingembodiments can be achieved by adapting the Bragg reflector structuresDBR1˜DBR4 in FIG. 13 to FIG. 16. Under the condition where the Braggreflector structure has a stacked structure with thickness gradient inreflective layers or has a stacked structure by multiple reflectivelayers having different thicknesses, the Bragg reflector structure iscapable to providing a broader reflective wavelength range.

FIG. 17 is a schematic cross-sectional view of an LED according to anembodiment of the invention. An LED 100A of FIG. 17 is similar to theLED 100 of FIG. 2. Therefore, like or corresponding components arereferred to with like or corresponding symbols. The LED 100A differsfrom the LED 100 in that insulation patterns 103A of the LED 100A differfrom the insulation patterns 103 of the LED 100. The followingdescriptions mainly focus on the difference. Like or corresponding partsmay be referred to the previous descriptions based on the symbols inFIG. 17, and will not be repeated in the following.

Referring to FIG. 17, the LED 100A includes the growth substrate 170,the first-type semiconductor layer 110, the emitting layer 120, thesecond-type semiconductor layer 130, the first electrode 140, the secondelectrode 150, a Bragg reflector structure 160′, the insulation patterns103A, the conductive layer 101, the insulating layer 105, and theelectrode pad 107. The emitting layer 120 is located between thefirst-type semiconductor layer 110 and the second-type semiconductorlayer 130. The first electrode 140 is electrically connected to thefirst-type semiconductor layer 110. The second electrode 150 iselectrically connected to the second-type semiconductor layer 130. Thefirst electrode 140 and the second electrode 150 are located on the sameside of the Bragg reflector structure 160′. The Bragg reflectorstructure 160′ is located between the second electrode 150 and thesecond-type semiconductor layer 130. The conductive layer 101 isdisposed between the Bragg reflector structure 160′ and the second-typesemiconductor layer 130. The insulation patterns 130A are disposedbetween the conductive layer 101 and the second-type semiconductor layer130. An area of the conductive layer 101 outside of the insulationpatterns 103A contacts the second-type semiconductor layer 130. Theinsulating layer 105 has a through hole O1, and the electrode pad 107 isfilled into the through hole O1, so that the electrode pad 107 iselectrically connected to the second electrode 150.

In particular, the Bragg reflector structure 160′ has the through hole166. In the present embodiment, the first type semiconductor layer 110,the emitting layer 120, the second type semiconductor layer 130, and theBragg reflector structure 160′ may be sequentially stacked on the firstsurface 171 of the growth substrate 170. The second electrode 150 isfilled into the through holes 166 to electrically connect with thesecond-type semiconductor layer 130. The second electrode 150 filledinto the through holes 166 may contact the conductive layer 101 to beelectrically connected to the second-type semiconductor 130 via theconductive layer 101.

Referring to FIG. 17, what differs from the LED 100 is that theinsulation pattern 130A has a first surface 103 f facing toward thesecond-type semiconductor layer 130 and a second surface 103 g facingaway from the second-type semiconductor layer 130. In particular, theinsulation pattern 103A further includes an inclined surface 103 hconnecting the first surface 103 f and the second surface 103 g. Theinclined surface 103 h is inclined with respect to the first surface 103f and the second surface 103 g. The insulation patterns 103A are capableto blocking a current. The conductive layer 101 and the insulationpatterns 103A may be disposed to disperse the current, so as to avoidthe current from concentrating at certain part of the emitting layer120, thereby allowing uniform distribution of the light emitting regionof the emitting layer 120.

In particular, as shown in FIG. 17, the first surface 103 f is incontact with the second-type semiconductor layer 130 and not in contactwith the conductive layer 101. The second surface 103 g and the inclinedsurface 103 h are in contact with the conductive layer 101 and not incontact with the second-type semiconductor layer 130. An orthogonalprojection area of the first surface 103 f on the second-typesemiconductor layer 130 is greater than an orthogonal projection area ofthe second surface 103 g on the second-type semiconductor layer 130, andthe inclined surface 103 h connects an edge of the area of the firstsurface 103 f and an edge of the area of the second surface 103 g. Anacute angle θ1 in the material of the insulation pattern 103A is formedbetween the inclined surface 103 h and the first surface 103 f. In thisembodiment, 10°≦θ1≦80°, and preferably 30°≦θ1≦50°. However, theinvention is not limited thereto.

FIG. 18A is a schematic enlarged view of an insulation pattern and aconductive layer according to an embodiment of the invention. FIG. 18Bis a schematic enlarged view of an insulation pattern and a conductivelayer of a comparative example. Referring to FIGS. 18A and 18B, in thecomparative example of FIG. 18B, an angle θ1′ is formed between asidewall 103 d and a bottom surface 103 e of the insulation pattern103A′, and θ1′≧90°. In the case that θ1′≧90°, when the conductive layer101 covers the insulation pattern 103A′, the coverage of the conductivelayer 101 on the sidewall 103 d of the insulation pattern 103A′ may bebad, and the coverage may be discontinued, instead of continuous, at thesidewall 103 d, thereby jeopardizing the electrical and opticalproperties of the LED chip and the reliability thereof. Comparatively,referring to FIG. 18A, the insulation pattern 103A has the inclinedsurface 103 h in this embodiment. The acute angle θ1 in the material ofthe insulation pattern 103A is formed between the inclined surface 103 hand the first surface 103 f. In the case that θ1′ is smaller than 90°,when the conductive layer 101 covers the insulation pattern 130A, thecoverage of the conductive layer 101 on the inclined surface 103 h ispreferable. Therefore, the electrical and optical properties of the LEDchip 100A and the reliability thereof may be enhanced. For example, withthe preferable coverage of the conductive layer 101 on the inclinedsurface 103 h, a driving voltage of the LED chip 100A may be lowered,uniformity of current density and brightness may be enhanced, and heatconcentration at a certain area may be avoided. In addition, thepreferable coverage of the conductive layer 101 also is also beneficialin formation of a process window of a layer on the conductive layer 101subsequently.

FIG. 19A is a schematic view illustrating an insulation patternaccording to an embodiment of the invention. Referring to FIG. 19A, aninsulation pattern 103A1 includes a plurality of first sub-layers SL1and a plurality of sub-layers SL2. The first sub-layers SL1 and thesecond sub-layers SL2 are alternately stacked. A material of the firstsub-layers SL1 and a material of the second sub-layers SL2 may differfrom each other. The material of the first sub-layers SL1 includestantalum pentoxide (Ta₂O₅), zirconium dioxide (ZrO₂), niobium pentoxide(Nb₂O₅), hafnium oxide (HfO₂), titanium dioxide (TiO₂), or combinationsthereof. The material of the second sub-layers SL2 includes siliconoxide (SiO₂).

When the insulation pattern 103A1 are manufactured by using the firstsub-layers SL1 and the second sub-layers SL2 formed of differentmaterials, a lift-off process may be selectively performed to form theinsulation pattern 103A1 having the inclined surface 103 h. In thisembodiment, a refractive index of the first sub-layers SL1 is differentfrom a refractive index of the second sub-layers SL2. In this way, theinsulation pattern 103A1 is capable of providing Bragg reflection. Whenthe insulation pattern 103A1 is used in the LED 100A of FIG. 17, theinsulation pattern 103A1 capable of providing Bragg reflection mayreflect a beam emitted from the emitting layer 120 toward the secondelectrode 150 elsewhere, so that the light beam emitted from theemitting layer 120 is less likely to be blocked by the light-shieldingsecond electrode 150 and may be emitted elsewhere. Therefore, thebrightness of the LED chip 100A may be increased.

As for other embodiments, FIG. 19B, for example, is a schematic viewillustrating an insulation pattern according to another embodiment ofthe invention. Materials of first sub-layers SL3 and second sub-layersSL4 of an insulation pattern 103A2 may be the same, whereas densities ofthe first sub-layers SL3 and the second sub-layers may be different. Thematerial of the insulation pattern 103A2 includes, for example, silicondioxide (SiO₂) or other materials having characteristic of currentblocking.

Desired densities of the first sub-layers SL3 and the second sub-layersSL4 formed of the same material but having different densities may beachieved by modulating process parameters (e.g., temperature, pressure,time, etc.). When the first sub-layers SL3 and the second sub-layers SL4formed of the same material but having different densities are used tomanufacture the insulation pattern 103A2, an etching process forpatterning may be performed to form the insulation pattern 103A2. Sincethe first sub-layers SL3 and the second sub-layers SL4 have differentdensities, when the first sub-layers SL3 and the second sub-layers SL4are etched at the same time, the sub-layers having a higher density(e.g., SL3) have a greater residual area, and the sub-layers having alower density (SL4) have a smaller residual area. Thus, the insulationpattern 103A2 may exhibit a structure having the inclined surface 103 h.

FIG. 20 is a schematic cross-sectional view of an LED according to anembodiment of the invention. An LED 200A of FIG. 20 is similar to theLED 200′ of FIG. 3. Therefore, like or corresponding components arereferred to with like or corresponding symbols. The LED 200A differsfrom the LED 200′ in that the insulation patterns 103A of the LED 200Adiffer from the insulation patterns 103 of the LED 200′. The followingdescriptions mainly focus on the difference. Like or corresponding partsmay be referred to the previous descriptions based on the symbols inFIG. 20, and will not be repeated in the following.

Retelling to FIG. 20, the LED 200A includes the growth substrate 170,the first-type semiconductor layer 110, the emitting layer 120, thesecond-type semiconductor layer 130, the first electrode 140, the secondelectrode 150, a Bragg reflector structure 260′, the insulation patterns103A, the conductive layer 101, the first insulating layer 105 a, thesecond insulating layer 105 b, at least one first metal layer 180, andat least one second metal layer 190.

The emitting layer 120 is located between the first-type semiconductorlayer 110 and the second-type semiconductor layer 130. The firstelectrode 140 is electrically connected to the first-type semiconductorlayer 110. The second electrode 150 is electrically connected to thesecond-type semiconductor layer 130. The first electrode 140 and thesecond electrode 150 are located on the same side of the Bragg reflectorstructure 260′.

The first insulating layer 105 a is disposed on the first-typesemiconductor layer 110, the second-type semiconductor layer 130, andsidewalls of the first-type semiconductor layer 110, the emitting layer120, and the second-type semiconductor layer 130. The first insulatinglayer 105 a may further dispose on part of the first metal layer 180,part of the second metal layer 190, and the conductive layer 101, and atleast part of the Bragg reflector structure 260′ is located between thefirst insulating layer 105 a and the second insulating layer 105 b. Thefirst metal layer 180 is located between the first electrode 140 and thefirst-type semiconductor layer 110, the second metal layer 190 islocated between the second electrode 150 and the second-typesemiconductor layer 130, and part of the Bragg reflector structure 260′is located on the first metal layer 180 or the second metal layer 190.

The Bragg reflector structure 260′ has the through holes 166 between thesecond electrode 150 and the second-type semiconductor layer 130 and thethrough holes 167 between the first electrode 140 and the first-typesemiconductor layer 110. In the present embodiment, the first typesemiconductor layer 110, the emitting layer 120, the second typesemiconductor layer 130, and the Bragg reflector structure 260′ may besequentially stacked on the first surface 171 of the growth substrate170. The second electrode 150 is filled into the through holes 166 toelectrically connect with the second-type semiconductor layer 130. Thefirst electrode 140 is filled into the through holethrough holes 167 toelectrically connect with the first-type semiconductor layer 110.

What differs from the LED 200′ is that the insulation pattern 130A hasthe first surface 103 f facing toward the second-type semiconductorlayer 130 and the second surface 103 g facing away from the second-typesemiconductor layer 130. In particular, the insulation pattern 103Afurther includes the inclined surface 103 h connecting the first surface103 f and the second surface 103 g. The inclined surface 103 h isinclined with respect to the first surface 103 f and the second surface103 g. The insulation patterns 103A are capable to blocking a current.The conductive layer 101 and the insulation patterns 103A may bedisposed to disperse the current, so as to avoid the current fromconcentrating at certain part of the emitting layer 120, therebyallowing uniform distribution of the light emitting region of theemitting layer 120. In particular, the insulation pattern 103 may beconfigured based on FIG. 19A or FIG. 19B.

FIG. 21 is a schematic cross-sectional view of an LED according to anembodiment of the invention. An LED 300A of FIG. 21 is similar to theLED 300′ of FIG. 4. Therefore, like or corresponding components arereferred to with like or corresponding symbols. The LED 300A differsfrom the LED 300′ in that the insulation patterns 103A of the LED 300Adiffer from the insulation patterns 103 of the LED 300′. The followingdescriptions mainly focus on the difference. Like or corresponding partsmay be referred to the previous descriptions based on the symbols inFIG. 21, and will not be repeated in the following.

Referring to FIG. 21, The LED 300A includes the first-type semiconductorlayer 110, the emitting layer 120, the second-type semiconductor layer130, the first electrode 140, the second electrode 150, and a Braggreflector structure 360′. The emitting layer 120 is located between thefirst-type semiconductor layer 110 and the second-type semiconductorlayer 130. The first electrode 140 is electrically connected to thefirst-type semiconductor layer 110. The second electrode 150 iselectrically connected to the second-type semiconductor layer 130. Thefirst electrode 140 and the second electrode 150 are located on the sameside of a Bragg reflector structure 360′.

In the present embodiment, the LED 300A further includes the insulationpatterns 103A. The insulation patterns 130A are disposed between theconductive layer 150 and the second-type semiconductor layer 130. TheLED 300A further includes the first insulating layer 105 a and thesecond insulating layer 105 b. The Bragg reflector structure 360′ isdisposed between the first insulating layer 105 a and the secondinsulating layer 105 b. The first insulating layer 105 a and the secondinsulating layer 105 b may be partially overlapped and in contact witheach other. The first insulating layer 105 a is disposed on thefirst-type semiconductor layer 110 and the second-type semiconductorlayer 130, and covers sidewalls of the first-type semiconductor layer110, the emitting layer 120, and the second-type semiconductor layer130. The second insulating layer 105 b may be disposed on the Braggreflector structure 360′. The through holes 166 penetrate through thesecond insulating layer 105 b and the first insulating layer 105 a. Thesecond electrode 150 is filled into the through holes 166 toelectrically connect with the second metal layer 190 and the second-typesemiconductor layer 130. The through holes 167 penetrate through thesecond insulating layer 105 b and the first insulating layer 105 a. Thefirst electrode 140 is filled into the through holes 167 to electricallyconnect with the first metal layer 180 and the first-type semiconductorlayer 110.

What differs from the LED 300′ is that the insulation pattern 130A hasthe first surface 103 f facing toward the second-type semiconductorlayer 130 and the second surface 103 g facing away from the second-typesemiconductor layer 130. In particular, the insulation pattern 103Afurther includes the inclined surface 103 h connecting the first surface103 f and the second surface 103 g. The inclined surface 103 h isinclined with respect to the first surface 103 f and the second surface103 g. The insulation patterns 103A are capable to blocking a current.The conductive layer 101 and the insulation patterns 103A may bedisposed to disperse the current, so as to avoid the current fromconcentrating at certain part of the emitting layer 120, therebyallowing uniform distribution of the light emitting region of theemitting layer 120. In particular, the insulation pattern 103 may beconfigured based on FIG. 19A or FIG. 19B.

FIG. 22 is a schematic cross-sectional view of an LED according to anembodiment of the invention. An LED 400A of FIG. 22 is similar to theLED chip 300A of FIG. 21. Therefore, like or corresponding componentsare referred to with like or corresponding symbols. Main differencesbetween the LED 400A and the LED chip 300A are described as follows. Inthe LED 400A, the first metal layer 180 includes the welding portion 180a and the finger portion 180 b. The second metal layer 190 includes thewelding portion 190 a and the finger portion 190 b. The first insulatinglayer 105 a and the second insulating layer 105 b may be partiallyoverlapped and in contact with each other. The first insulating layer105 a is disposed on the first-type semiconductor layer 110 and thesecond-type semiconductor layer 130, and covers side walls of thefirst-type semiconductor layer 110, the emitting layer 120, and thesecond-type semiconductor layer 130. The first insulating layer 105 a isdisposed on part of the first metal layer 180, part of the second metallayer 190, and the conductive layer 101.

More specifically, the first insulating layer 105 a is disposed on partof the welding portion 180 a of the first metal layer 180 and the fingerportion 180 b of the first metal layer 180. Part of the Bragg reflectorstructure 360′ is located between the first insulating layer 105 a andthe second insulating layer 105 b. The second insulating layer 105 b maybe disposed on the Bragg reflector structure 360′. The second insulatinglayer 105 b may encapsulate the Bragg reflector structure 360′. Thesecond insulating layer 105 b is disposed above part of the weldingportion 180 a of the first metal layer 180 and the finger portion 180 bof the first metal layer 180.

The through holes 166 penetrate through the second insulating layer 105b and the first insulating layer 105 a. The second electrode 150 isfilled into the through holes 166 to electrically connect with thewelding portion 190 a of the second metal layer 190 and the second-typesemiconductor layer 130. The through holes 167 penetrate through thesecond insulating layer 105 b and the first insulating layer 105 a. Thefirst electrode 140 is filled into the through holes 167 to electricallyconnect with the welding portion 180 a of the first metal layer 180 andthe first-type semiconductor layer 110. Effects and characteristics ofthe LED 400A are similar to those of the LED 300A. Thus, details inthese respects will not be repeated in the following. What differs fromthe LED 300′ is that the insulation pattern 130A has the first surface103 f facing toward the second-type semiconductor layer 130 and thesecond surface 103 g facing away from the second-type semiconductorlayer 130. In particular, the insulation pattern 103A further includesthe inclined surface 103 h connecting the first surface 103 f and thesecond surface 103 g. The inclined surface 103 h is inclined withrespect to the first surface 103 f and the second surface 103 g.

FIGS. 23 and 24 are schematic cross-sectional views of an LED accordingto an embodiment of the invention. A schematic top view of an LED 500Aof FIGS. 23 and 24 is similar to the schematic top view of the LED 500of FIG. 7. In particular, FIG. 23 corresponds to the cross-sectionalline C-D of FIG. 7, and FIG. 24 corresponds to the cross-sectional lineG-H of FIG. 7. The schematic top view of the LED 500A may be referred toFIG. 7, and details in this respect will thus not be repeated in thefollowing. The LED 500A of FIGS. 23 and 24 is similar to the LED 500′ ofFIGS. 10 and 12. Therefore, like or corresponding components arereferred to with like or corresponding symbols.

The LED 500A differs from the LED 500 in that the insulation patterns103A of the LED 500A differ from the insulation patterns 103 of the LED500. The following descriptions mainly focus on the difference. Like orcorresponding parts may be referred to the previous descriptions basedon the symbols in FIGS. 7, 23, and 24, and will not be repeated in thefollowing.

Referring to FIGS. 7, 23, and 24, The LED 500A includes the first-typesemiconductor layer 110, the emitting layer 120, the second-typesemiconductor layer 130, the first electrode 140, the second electrode150, and a Bragg reflector structure 560′. The emitting layer 120 islocated between the first-type semiconductor layer 110 and thesecond-type semiconductor layer 130. The first electrode 140 iselectrically connected to the first-type semiconductor layer 110. Thesecond electrode 150 is electrically connected to the second-typesemiconductor layer 130. The first electrode 140 and the secondelectrode 150 are located on the same side of a Bragg reflectorstructure 560′.

As illustrated in FIG. 7 and FIG. 23, at the recesses N140 of the firstelectrode 140, the first-type semiconductor layer 110, the emittinglayer 120, the second-type semiconductor layer 130, the insulationpatterns 103A, the conductive layer 101, the second metal layer 190, andthe Bragg reflector structure 560′ are sequentially stacked on thegrowth substrate 170. The profiles of the insulation patterns 103Acorrespond to the profile of the second metal layer 190 and the two areoverlapped with each other. Specifically, the second metal layer 190illustrated in FIG. 23 includes the finger portion 190 b, and the fingerportion 190 b is correspondingly located within the recesses N140 of thefirst electrode 140 and thus is not overlapped with the first electrode140. Moreover, the Bragg reflector structure 560′ overlaps the fingerportion 190 b.

As illustrated in FIG. 7 and FIG. 24, in the area of the secondelectrode 150, the first-type semiconductor layer 110, the emittinglayer 120, the second-type semiconductor layer 130, the insulationpatterns 103A, the conductive layer 101, the second metal layer 190, andthe Bragg reflector structure 560′ are sequentially stacked on thegrowth substrate 170. The profiles of the insulation patterns 103Acorrespond to the profile of the second metal layer 190 and the two areoverlapped with each other. Specifically, in FIG. 24, the weldingportion 190 a of the second metal layer 190 is overlapped with thesecond electrode 150 and the Bragg reflector structure 560′ isdisconnected in a region corresponding to the welding portion 190 a, soas to allow the welding portion 190 a of the second metal layer 190 tophysically and electrically connect with the second electrode 150. Inother words, the welding portion 190 a of the second metal layer 190 isnot overlapped with the Bragg reflector structure 560′.

As illustrated in FIGS. 7, 23, and 24, both the first metal layer 180and the second metal layer 190 include a part overlapped with the Braggreflector structure 560′ and another part not overlapped with the Braggreflector structure 560′. Part of the metal layer (i.e., part of thefirst metal layer 180 or part of the second metal layer 190) overlappedwith the Bragg reflector structure 560′ is not overlapped with the firstelectrode 140 and the second electrode 150. In this way, the thicknessof the LED 500A may be more uniform, which helps improve the yield whenbonding the LED 500 to other components.

What differs from the LED 500 is that the insulation pattern 130A hasthe first surface 103 f facing toward the second-type semiconductorlayer 130 and the second surface 103 g facing away from the second-typesemiconductor layer 130. In particular, the insulation pattern 103Afurther includes the inclined surface 103 h connecting the first surface103 f and the second surface 103 g. The inclined surface 103 h isinclined with respect to the first surface 103 f and the second surface103 g. The insulation patterns 103A are capable to blocking a current.The conductive layer 101 and the insulation patterns 103A may bedisposed to disperse the current, so as to avoid the current fromconcentrating at certain part of the emitting layer 120, therebyallowing uniform distribution of the light emitting region of theemitting layer 120. In particular, the insulation pattern 103 may beconfigured based on FIG. 19A or FIG. 19B.

In view of the foregoing, in the light emitting diode according to anembodiment of the invention, the sidewall of the Bragg reflectorstructure is an inclined surface. Therefore, a layer (e.g., the secondelectrode) disposed on the Bragg reflector structure may properly coverthe Bragg reflector structure, so as to facilitate the performance ofthe light emitting diode.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. A light emitting diode, comprising: a first-typesemiconductor layer; an emitting layer a second-type semiconductorlayer, wherein the emitting layer is located between the first-typesemiconductor layer and the second-type semiconductor layer; a firstelectrode, electrically connected to the first-type semiconductor layer;a second electrode, electrically connected to the second-typesemiconductor layer; and a Bragg reflector structure, wherein the firstelectrode and the second electrode are located on the same side of theBragg reflector structure; a conductive layer, disposed between theBragg reflector structure and the second-type semiconductor layer; and aplurality of insulation patterns, disposed between the conductive layerand the second-type semiconductor layer, wherein an area of theconductive layer outside the insulation patterns contacts thesecond-type semiconductor layer, and each of the insulation patterns hasa first surface facing toward the second-type semiconductor layer, asecond surface facing away from the second-type semiconductor layer andan inclined surface connecting the first surface and the second surfaceand inclined with respect to the first surface and the second surface.2. The light emitting diode as recited in claim 1, wherein an acuteangle θ1 is formed between the inclined surface and the first surface ina material of each of the insulation patterns.
 3. The light emittingdiode as recited in claim 2, wherein 10°≦θ1≦80°.
 4. The light emittingdiode as recited in claim 2, wherein 30°≦θ1≦50°.
 5. The light emittingdiode as recited in claim 1, wherein each of the insulation patternscomprises a plurality of first sub-layers and a plurality of secondsub-layers, and the first sub-layers and the second sub-layers arestacked alternately.
 6. The light emitting diode as recited in claim 5,wherein a material of each of the first sub-layers is different from amaterial of each of the second sub-layers.
 7. The light emitting diodeas recited in claim 5, wherein a material of each of the firstsub-layers is the same as a material of each of the second sub-layers,and a density of each of the first sub-layers is different from adensity of each of the second sub-layers.
 8. The light emitting diode asrecited in claim 1, wherein a reflectance of the Bragg reflectorstructure is greater than or equal to 95% in a reflective wavelengthrange at least covering 0.8X nm to 1.8X nm, the emitting layer isadapted to emit a beam, the beam has a peak wavelength within anemission wavelength range, and X is the peak wavelength of the emissionwavelength range.
 9. The light emitting diode as recited in claim 1,wherein the first-type semiconductor layer comprises a first portion anda second portion, the emitting layer is stacked on the first portion,the second portion extends out of an area of the emitting layer from thefirst portion, so as to electrically connect with the first electrode,and the first electrode, the emitting layer, the second-typesemiconductor layer, and the second electrode are located on a firstside of the first-type semiconductor layer.
 10. The light emitting diodeas recited in claim 1, wherein the Bragg reflector structure is locatedon the first side of the first-type semiconductor layer, the Braggreflector structure is at least located between the second electrode andthe second-type semiconductor layer, the Bragg reflector structurecomprises a plurality of through holes, and the second electrode isfilled into the through holes to electrically connect with thesecond-type semiconductor layer.
 11. The light emitting diode as recitedin claim 10, wherein the insulation patterns correspond to the throughholes.
 12. A light emitting diode, comprising: a first-typesemiconductor layer; an emitting layer a second-type semiconductorlayer, wherein the emitting layer is located between the first-typesemiconductor layer and the second-type semiconductor layer; a firstelectrode, electrically connected to the first-type semiconductor layer;a second electrode, electrically connected to the second-typesemiconductor layer; and a Bragg reflector structure, wherein the firstelectrode and the second electrode are located on the same side of theBragg reflector structure; a conductive layer, disposed between theBragg reflector structure and the second-type semiconductor layer; and aplurality of insulation patterns, disposed between the conductive layerand the second-type semiconductor layer, wherein an area of theconductive layer outside the insulation patterns contacts thesecond-type semiconductor layer, each of the insulation patternscomprises a plurality of first sub-layers and a plurality of secondsub-layers, and the first sub-layers and the second sub-layers arealternately stacked.
 13. The light emitting diode as recited in claim12, wherein a material of each of the first sub-layers is different froma material of each of the second sub-layers.
 14. The light emittingdiode as recited in claim 12, wherein a material of each of the firstsub-layers is the same as a material of each of the second sub-layers,and a density of each of the first sub-layers is different from adensity of each of the second sub-layers.
 15. The light emitting diodeas recited in claim 12, wherein a reflectance of the Bragg reflectorstructure is greater than or equal to 95% in a reflective wavelengthrange at least covering 0.8X nm to 1.8X nm, the emitting layer isadapted to emit a beam, the beam has a peak wavelength within anemission wavelength range, and X is the peak wavelength of the emissionwavelength range.
 16. The light emitting diode as recited in claim 12,wherein the first-type semiconductor layer comprises a first portion anda second portion, the emitting layer is stacked on the first portion,the second portion extends out of an area of the emitting layer from thefirst portion, so as to electrically connect with the first electrode,and the first electrode, the emitting layer, the second-typesemiconductor layer, and the second electrode are located on a firstside of the first-type semiconductor layer.
 17. The light emitting diodeas recited in claim 16, wherein the Bragg reflector structure is locatedon the first side of the first-type semiconductor layer, the Braggreflector structure is at least located between the second electrode andthe second-type semiconductor layer, the Bragg reflector structurecomprises a plurality of through holes, and the second electrode isfilled into the through holes to electrically connect with thesecond-type semiconductor layer.
 18. The light emitting diode as recitedin claim 17, wherein the insulation patterns correspond to the throughholes.